纳秒电脉冲作用下KcsA-膜蛋白体系电穿孔的分子动力学模拟（英文）

电穿孔是由外加电场诱导细胞膜产生孔洞的过程,目前已经广泛地用于生命科学相关的实验研究中,同时在临床应用方面显示出了越来越多的潜力。真空电子器件可产生强电磁脉冲,从而可以用来引起细胞膜的电穿孔,为了从分子层面研究KcsA-膜蛋白体系电穿孔的物理机制,利用分子动力学的方法,计算模拟了不同幅值纳秒电脉冲作用下KcsA-膜蛋白体系的穿孔过程。结果表明,随着纳秒电脉冲幅值的增大,体系穿孔完成所需的时间减小,同时孔出现的位置距KcsA蛋白较远,这一研究为电穿孔在生物医学方面的应用提供了相应的理论指导。

纳秒电脉冲致人卵巢癌细胞DNA损伤的时间效应

本研究旨在探讨纳秒电脉冲(nsEP)对人卵巢癌细胞铂敏感株A2780及铂耐药株C30的DNA损伤效应。将A2780和C30分别作用于场强为6kV/cm,脉宽为24ns的脉冲电场处理60s。假处理组予假脉冲处理。nsEP处理后0h、4h、8h、12h和24h采用CCK-8法检测细胞生存率;采用碱性单细胞凝胶电泳实验(彗星实验)检测细胞DNA损伤,测定彗星尾长(TL)、尾矩(TM)和Olive尾矩(OTM)的75th百分位数。结果显示随着时间增加,A2780和C30细胞的生存率和彗星形成率均先降低后增加,8h时最低(P<0.05);C30细胞的生存率高于A2780细胞(P<0.05),彗星形成率低于A2780细胞(P<0.05);C30细胞的TL、TM和OTM均低于A2780细胞(P<0.05);细胞死亡率和彗星形成率呈正相关(r=0.997,P<0.05;r=0.998,P<0.05)。结果表明,nsEP对人卵巢癌铂敏感细胞株和铂耐药细胞株的DNA损伤效应存在差异;nsEP致细胞死亡与DNA损伤相关。

纳秒级电脉冲信号的检测与计量实用技术

介质静电放电产生的纳秒级微电流脉冲会干扰高频电子电路的正常工作,对这种纳秒级电脉冲信号进行准确检测与计数是采取措施消除其对高频电路的影响的必要前提。本文着重研究这种纳秒脉宽、皮安级电流脉冲的检测与计数方法,并对器件选择与脉冲信号的传输作重点描述。

Study of the selective effect on cells induced by nanosecond pulsed electric field with the resistor-capacitor circuit model

A resistor-capacitor(RC)circuit model is proposed to study the effect of nanosecond pulsed electricfield on cells according to the structure and electrical parameters of cells.After a nanosecond step fieldhas been applied,the variation of voltages across cytomembrane and mitochondria membrane both in nor-mal and in malignant cells are studied with this model.The time for selectively targeting the mitochondriamembrane and malignant cell can be evaluated much easily with curves that show the variation of voltageacross each membrane with time.Ramp field is the typical field applied in electrobiology.The voltagesacross each membrane induced by ramp field are analyzed with this model.To selectively target the mito-chondria membrane,proper range of ramp slope is needed.It is relatively difficult to decide the range ofa slope to selectively affect the malignant cell.Under some conditions,such a range even does not exist.

Transmutations by Nanosecond Electromagnetic Impulses

Some experiments on radiation of hydrocarbons and the alloys including Bismuth and Lead by power nanosecond electromagnetic pulses are described. The list of the used equipment and technique of experiments are given. The result of these experiences is change of a chemical composition of the irradiated samples in comparison with the initial ones. Conversion of part of Bismuth to Lead is observed. The hypothesis of such changes is made.

Nanosecond Pulse Treatment on Water and Water Solutions

The experiment results of the nanosecond electromagnetic pulses action on water and water solutions containing radionuclides are described. An activity decrease of radionuclides solution is observed in many experiments. The results may be useful to create water purification devices from heavy metals and radionuclides.

光时域反射-光纤光栅传感系统中双激光器的驱动设计

为了扩大应变测量的范围,提出了使用两个分布反馈式(DFB)激光器作为光时域反射-光纤光栅(OTDR-FBG)传感系统的光源的方法,并设计了相应的纳秒脉冲驱动电路和温控电路,得到两个激光器的驱动脉冲宽度分别为3.10ns和3.18ns,脉冲幅值分别为4.40V和4.08V,温度控制电路精度达到±0.04℃。经测试得到的纳秒脉冲和温控精度满足OTDR-FBG传感系统的要求。